Warning-light housing

ABSTRACT

A warning-light housing of unitized construction having an integral reflector and lens. A receptacle is mounted to the housing and the receptacle, lens, and reflector are each in a fixed predetermined position relative to the other. The reflector surface has distributed random irregularities for uniform dispersion of light.

United States Patent Karl W. Abendroth Rochester, N.Y.

Dec. 3, 1969 Aug. 3, 1971 General Signal Corporation [72] Inventor [21App]. No. [22] Filed [45] Patented [73] .Assignee [54] WARNING-LIGHTHOUSING 10 Claims, 6 Drawing Fl [52] 0.8. (I 240/41.3, 240/1 1.2,240122, 240/41.36, 240/47, 2401103 [51] Int. Cl. F21v 13/04 [50] Fieldelse-rel 240/41.3, 10.66, 11.2, 22, 23, 27, 28, 41.36, 41.5, 41.55,103

[56] References Cited UNITED STATES PATENTS 1,915,842 6/1933 \Vinkler240/103 2,010,834 8/1935 Wottring 240/41.3 X

2,063,781 1/1937 Wendel 2,211,258 8/1940 Delfel...... 240/103 X2,245,755 6/1941 Carpenter 240/8.4 X 2,387,038 10/1945 Owens 240/103 X3,049,614 8/1962 Eikenberry 240/41.3 3,076,891 2/1963 Moore 240/10.663,119,567 1/1964 Schwartz.... 240/47 3,204,093 8/1965 Heenan 240/41.33,286,039 11/1966 Smith 240/1 1.2

Primary Examiner-Samuel 8. Matthews Assistant ExaminerRichard M. SheerAttorney- Harold S. Wynn ABSTRACT: A waming-light housing of unitizedconstruction having an integral reflector and lens. A receptacle ismounted to the housing and the receptacle, lens, and reflector are eachin a fixed predetermined position relative to the other. The reflectorsurface has distributed random irregularities for uniform dispersion oflight.

PATENTED AUG 3 B7! SHEET 1 0F 4 INVENTOR.

'K. W. ABENDROTH HIS ATTORNEY PATENTED Am; 3197! SHEET 2 BF 4 E4 moEm NWv/E INVENTOR. K. w. ABEN'DROTH ms ATTORNEY PATENTEU AUG 3 I971 SHEET 3OF 4 INVENTOR K. W. ABENDROTH Wig/g HIS ATTORNEY PATENTEU Am; 31971 FIG.4

INVENTOR. K. W. ABENDROTH HIS film FIG. 5

WARNING-LIGHT HOUSING BACKGROUND OF THE INVENTION This invention relatesto light signals and in particular to a warning-light-signal housing ofunitized construction.

There are a great number of light-signal housings in the prior art,however, they are hampered by various problems in maintenance, criticalfocusing and resistance to environmental conditions. A typical apparatushas a great many individual parts, and in addition, lamps of this typeoften must be powered in remote areas, and as a consequence, batteriesmust be supplied. It is therefore desirable to get as much lightprojected over the proposed field of view with as little power drain aspossible. In addition, warning-light housings of the prior art must beequipped with apparatus for critically adjusting the position of thelight source so that it is within the focus of the reflector. Thisrequires expensive and complex apparatus and a time-consuming focusingprocedure.

Another basic problem of prior art warning-light housings is the effectof environment of the device over the years. These devices aresusceptible to corrosion, and must be periodically painted, further thelends may be damaged by objects cast at it from any number of sources.As a result, field repairs are necessitated which are costly and timeconsuming.

This invention has for its purpose the solution of the above problems byinstallation of a new and economical structure.

It is therefore an object of this invention to provide an economical andsimply constructed warning-light housing.

It is another object of this invention to provide an optical system ofgreater efiiciency.

It is yet another object of the invention to provide a housing whichreduces damaging effects of environment.

SUMMARY OF THE INVENTION In accordance with the present invention thereis provided a warning-light housing of unitized construction. Thehousing consists of an arcuate reflector integrally molded into a basemember having an access port. A lens member and receptacle are alsomounted to the base member. The lens member, receptacle and integralreflector are each aligned in a predetermined position relative to theother.

In accordance with another aspect, the invention provides a reflectorhaving substantially uniformly distributed random irregularities overits surface which slightly disperses light. The reflector is generallyof an arcuate concave shape.

In accordance with yet another aspect of the invention a circularbackground is provided having the shape of substantially uniformlyconcentrically spaced waves along a radially transverse direction.

For a better understanding of the present invention, together with otherand further objects thereof, reference is had to the followingdescription, taken in connection with the accompanying drawings.

. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional side elevationof the preferred embodiment of the invention.

FIG. is a sectional elevation of a prior art device.

FIG. 3 is a front elevation of the preferred embodiment of FIG. 1 with asectional segment removed.

FIG. 3A is a sectional elevation of FIG. 3 along line 3A-3A.

FIG. 4 is a schematic diagram used in the discussion of focusingtechniques.

FIG. 5 is a schematic diagram used in the discussion of aimingprocedures.

DESCRIPTION OF THE PREFERRED EMBODIMENT The "preferred embodiment of theinvention is now described with reference to FIG. 1. The housingincludes a number of integrally constructed molded component parts.

The material used in the preferred embodiment is molded plastic from thepolycarbonate and polyethylene groups, but is is obvious that anysuitable material can be used. The molding of components does not merelymeans separately molded components but a combining of functions ofvarious components into one or more unitized parts. The housing 10includes an integral reflector 12 and provides a receptacle 13 foraccepting a lamp 14. Windows 15 and a vent screen 9 are placed in thesides of the base 11. A door 16 is movably mounted on the base 11 by ahinge 20. The door 16 is of integral construction comprising a ring 19to which is mounted a hood l7 incorporating a lens 18.

The lens 18 is in a predetermined position with respect to the reflector12 when the door 16 is closed. A backgroundforming member 22 is mountedover the hood 17 about the ring 19. The reflector 12 has uniformlydistributed random irregularities 28 over its surface which is shown indetail in FIG. 4, the purpose of the irregularities 28 is more fullyexplained hereinafter. The receptacle 13 is in a predetermined positionsuch that a filament 31 in the bulb 14 will lie substantially at thefocus of the reflector 12. As indicated in FIG. 1, the bulb 14 isconstructed so that the filament 31 has a fixed relation withbulb-alignment pins 32; the filament 31 is shown parallel to and at afixed distance from the pins. It should be noted that any bulbarrangement of precise alignment may be used.

The door 16 movably mounted on the base 11 permits access to theinterior of the housing 10. Hinge 20 is used in this particularembodiment because it is compatible with prior art devices now in use asshown in FIG. 2. It is of particular advantage to this embodiment thatit be compatible with the currently used devices for a number ofreasons. One important reason is that old systems can be repaired by useof the replacement parts of the new device, e.g., the lens 41 may bedamaged and it is advantageous and time saving to replace not only lens41 but also ring 42, hood 43, and background 44. This not onlyaccomplishes repair but more importantly updates the equipment to thelatest design features.

Background-forming member 22 has a different configuration from priorart devices and is mounted on the door 16 by means of a snap-fit. Asshown in FIG. 3A, a lip 23 of background-forming member 22 is rigidlyheld by the combination of ridge 24, groove 25, and stop 26 on the door16. By exerting pressure on the body of the background-forming member22, the lip 23 gives way and passes over ridge 24 and lip 23 snaps intogroove 25. It is obvious that although a snap fit is used in thisillustration, a one-piece mold of the door 16 and background-formingmember 22 could be easily accomplished by a change in tooling.

Another aspect of the background-forming member 22 design is illustratedin FIGS. 3 and 3A. It has no mounting screw holes as in the old typebackground but is molded as a single piece having a snap-fitconstruction. Background-forming member 22 is made of a semirigid blackplastic in the preferred embodiment and will withstand the effects ofvibration, vandalism, and adverse weather conditions. The side viewshown in FIG. 3A illustrates that background-forming member 22 is not athick plastic mold but rather a thin plate which has waves 36. The waves36 provide compliance yet give a great deal of strength. Thisconstruction which is not only economically advantageous but alsoextremely durable, makes the background-forming member 22 designextremely useful in railroad application.

As previously pointed out, the door 16 includes a lens 18, and a ring 19and a hood 17 as one molded part.Referring to the prior art device ofFIG. 2, a lens 41, a hood 43, and a ring 42 are fastened together andthen installed on the base 45. The advantages of the simplifiedconstruction of the preferred embodiment are thusly apparent. Forexample, in a particular application of the lamp used as agrade-crossing warning light, a red-colored lens 18 is used. Toimplement this requirement, the entire door 16 including the lens 18,hood l7, and ring 19 are molded out of red plastic, and the lens 18 ismasked while the interior of the door is painted black. Thus the door 16is not only simply constructed, but weather resistant because the paintis not exposed to the environment therefore obviating rapiddeterioration. The windows of the base 11 may be incorporated in anynumber of ways similar to the lens 18 construction but in thisembodiment they are snap fit into place, serving to allow viewing todetermine whether the signal is operating. Various combinations ofmold-snap fits and multicolor molding may be used depending on thesituation and the application desired.

The vent screen 9 is integrally molded into the bottom of the basemember 11 and allows air circulation within the unit for temperatureequalization.

In view of the foregoing description of the alternative constructiontechniques, unitized does not necessarily means one signal mold. Itmeans rather that any number of molded component parts compatible withthe prior art devices are provided, while many parts not essential tothe functioning of the apparatus are removed, e.g., fasteners areeliminated by molding and snap-fit construction. It is thereforeimportant to not that unitized refers more precisely to an optimumnumber of molded components preferably compatible with prior artdesigns.

As was indicated earlier in the discussion, the preferred use of theinvention is in a highway grade-crossing signal and in that particularapplication, a red-colored lens 18 is required. In such application itis desirable that a reflective material be used which resists corrosioneffectively. Gold is a material which while quite expensive meets therequired criteria. By present state-of-the-art techniques, a very smallamount of gold can be vacuum deposited on the surface of the reflector12. Gold, while not the best reflective material, reflects the redspectrum with sufficient efficiency for the application shown in thepreferred embodiment. In addition, only a small amount of gold isnecessary in vacuum depositing. It should be recognized, however, thatthe surface could be coated with other reflective materials such aschromium, aluminum or silver, well known to those skilled in the art fordifferent applications.

Turning to FIG. 4, a detail sectional view of the reflector R having arippled surface" is shown. The reflector R in the preferred embodimentis generally the shape of a parabola but any surface which reflectslight rays on a substantially parallel configuration is sufficient aswill be pointed out later. The reflector need not strictly conform to atrue parabolic section because the rippled surface" introduces anintentional error factor. Thus the less precise requirement for surfaceaccuracy reduces the cost of the device, among other advantages. Thisreflector 12 may be used not only as the preferred embodiment of FIG. 1,but may be mounted in the rear of the prior art device of FIG. 2 inplace of the smooth reflector 46. In either application, the reflector Rdisplays its unique characteristics.

The "rippled surface reflects a substantially full and evenlydistributed beam of light with only a slight spread or divergence of therays. In conventional smooth surface parabolic reflectors if a lightsource is placed at the focus F, rays of light emanating from the sourcefollow the path FSN, while the reflected ray SN is parallel to thereflector axis AA. However, if the surface of the reflector is notaccurately formed, the rays will follow paths FSU or FSD. Assuming asegment of the surface area of the reflector is not shaped properly,then a portion of the available light is reflected away from itsintended path. This phenomenon can be observed in prior art reflectorsand is referred to as a dark spot". If, however, the entire surface ofthe reflector R is substantially the shape of a parabola as shown inFIG. 4, and the surface has uniformly distributed random irregularities,then the light reflected with the source at focus F is substantiallyuniformly projected about the axis AA. That is, the beam of reflectedlight while diverting from axis AA, depending on the degree ofirregularities in the surface, is quite uniform in illumination. Ifobserved, the reflector exhibits no dark spots," the multipleirregularities on the surface of the reflector tend to cancel theeffects of slight surface errors and give a uniform beam of light.

To enable a more incisive understanding of this phenomenon, assume nnumber of points in the surface of the reflector R, when n is large andthe uniform random irregularities over the reflector surface are veryslight, there will be a reflected distribution of light rays divergingslightly from a direction along axis AA. This results in a distributioncentered about AA. The rippled reflector 12 of FIG. 1 approaches thiscondition and as the reflected light is observed, it appears to beuniformly distributed. The slight errors or irregularities over thesurface of the reflector 12 give the illusion of a uniform beam oflight.

The use of the rippled mirror further makes critical focusingunnecessary, so that the complex focusing apparatus 29 used in the priorart device of FIG. 2 is eliminated and the simplified receptacle 13 ofFIG. 1 may replace it. Further, since the reflected light beam from therippled surface is purposely divergent about the axis AA, placing of thelight source at the precise focus is unnecessary. The foregoing isdemonstrated with reference to FIG. 5. The focus F of the reflector liesin the axis AA. The plane P is normal to the axis AA and a circle ofradius r lies in the plane P. For purposes of the preferred embodimentof FIG. 1, the filament 31 although preferably normal to the plane Palong axis AA and evenly distributed on each side of focus F, need onlyintersect the plane P within the perimeter of the circle of radius r.Practically speaking, if r is sufficiently small, i.e., in the order ofone thirty-second of an inch, this results in in a normally sufficientamount of light being reflected.

It is important with respect to FIG. 5 to note that if the filament isnot quite in the focus F, then the reflected cluster of light rays willhave a direction slightly different from axis AA. When the filament ofthe lamp is precisely in the focus F, the axis of the reflector r iscolinear with the axis of the axis of the reflected light beam, however,if the filament is slightly out of focus, the beam oflight will have anaxis BB slightly askew of AA. This direction can be measured by theangle 0, formed by the intersection of the line drawn from the positionof the filament 31 at F to the vertex of the reflector V and the axis ofthe reflector along AA. When the filament 31 is in the circular areadefined previously, then this angle F 'VA is very small and thedirection of the beam of light can be adjusted by aiming the housing 10rather than adjusting the filament 31.

In a typical illustration of the signal light of FIG. 1, the housing 10is mounted on a highway standard (not shown) to a nipple extension 48 bynipple connection 33. The housing 10 is free to rotate horizontallyabout the nipple extension 33 and tilt vertically about the nippleextension 48. To achieve optimum intensity, the housing is moved whilebeing observed at a reference position on the highway. In other words,if a substantial beam of light is passed through the lens 18 down thehighway, it can be aimed at a specific reference without the necessityof focusing, therefore eliminating an expensive and time-consumingprocedure.

While this unit will operate satisfactorily with the usual 10 volt-l8watt lamp, it is suggested that a 24 volt-50 watt lamp be used. Thisyields a very good indication on 24 volts AC, and a satisfactoryindication on 10 volts battery during power off. Battery drain duringthis situation is comparable to that of the 10 volt-l 8 watt lamps.While most colors do not permit this phenomenon to occur with enoughefficiency to be useful when used in conjunction with a red lens, theeffect is a signal as efficient as any signal available in the art.

Another innovation, in the optical system used, of this invention isthat the light is projected where it is most needed. Prior art devicesgenerally project a beam of light at a relatively constant intensityover a wide angle of observation. The lens 18 shown in FIG. 3 is acombination ofa center area 47 and a spread light area 46. The spreadlight area is an area having a series of prisms which spread some of thelight down and to the sides for close up and peripheral viewing, whilethe center area 47 is not a lens at all in that it has no focal point.It is a center area 47 of molded plastic and has properties of planeglass. It is not intended for the center lens area 47 to disperse the,light beam, rather the rippled mirror 12 affects this purpose. lnconjunction with prior art reflectors, lens 18 projects the majority ofa beam of light of high intensity over a narrow angle of observation,with little or no spread and disperses some light down and to the sides.The majority of the light is projected over the center beam 47 withslight spread and a minimal amount is dispersed down and to the sidesover a large angle of the order of 30 in the spread light area 46. Withthe addition of the divergence introduced by a rippled mirror reflector,it spreads the high intensity beam to approximately 5. This combinationof wide angle low intensity at close range and high intensity smallangle at long range is useful particularly in highway grade-crossingwarning signals.

Thus, it is seen that the optical system of this invention harnesses thenormally deleterious effects of reflector distortion and produces a moreefficient and reliable light source'at lower cost. It uses that whichhas heretofore been considered useless and troublesome to a constructiveend.

The embodiment of this invention as shown in FIG. 1 combines variousfeatures, including, unitized construction of component parts adaptableto existing housings, a more resilient device, more effectiveutilization of the available light, a simple manufacturing andinstallation procedure, and overall cost reduction and produces a signalhousing having improved characteristics over prior art devices.

While there has been shown what is at present considered to be thepreferred embodiment of the invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the invention.

What I claim is:

l. A warning-light housing of unitized construction comprising:

a base member having an access port;

a concave arcuate reflector integrally mounted to the base member;

a lens member mounted to the base member;

a receptacle mounted to the base member;

the lens member, the receptacle and the reflector each aligned inpredetermined position relative to the other and a background-formingmember of substantially circular shape, the background-forming memberhaving means for attachment to the warning light housing, and thebackground-forming member having a shape substantially concentricallywaved along a radially transverse direction.

2. The housing of claim 1 wherein the reflector has substantiallyuniformly distributed random irregularities over its surface.

3. A warning-light housing of unitized construction comprising:

a base member having an access port;

a door mounted to the base member for closing the access port;

a concave arcuate reflector integrally mounted to the base member;

a receptacle mounted to the base member;

a lens integrally mounted to the door such that when the door is in aclosed position, the lens, the reflector and the receptacle are eachaligned in predetermined position relative to the other and abackground-fonning member of substantially circular shape, thebackground-forming member having means for attachment to thewarninglight housing, and the background-forming member having a shapesubstantially concentrically waved along a radially transversedirection.

4. The warning-light housing of claim 3 wherein the reflector hasunifonnly distributed random irregularities over its surface; and a hoodis mounted to the door about the periphery ofthe lens.

5. The warning-light housing of claim 4 wherein; the receptacle has aterminal block attached thereto for electrical connection with alightsource, and the receptacle holds the light source in an alignedpredetermlned position relative to the lens and reflector so that nofocusing adjustment is necessary.

6. The warning-light housing of claim 5 wherein;

a mounting nipple is attached to the base member;

a window is mounted in the side of the base member; and

a vent is mounted in the side of the base member.

7. The warning-light housing of claim 6 having an integrally mountedreceptacle.

8. A warning-light housing comprising:

an arcuate concave reflector,

the reflector having substantially uniformly distributed randomirregularities over its surface of producing uniform light dispersion;and

a background-forming member of substantially circular shape, thebackground-forming member having means for attachment to thewarning-light housing, the background-forming member having a shapesubstantially concentrically waved, along a radially transversedirection.

9. The reflector of claim 8 having substantially the shape of aparabolic section wherein:

a reflective material is deposited upon the surface, the reflectivematerial selected from the group consisting of gold, silver, chromium,and aluminum.

10. A warning-light housing of unitized construction comprising incombination:

a base member of tubular cylindrical shape, the base having an open andclosed end; I

an integral reflector mounted in the closed end of the base with theconcave surface facing the open end, being substantially the shape of aparabolic dish, and having uniformly distributed random irregularitiesover its concave surface;

the concave surface plated with a reflective material;

a receptacle mounted to the base member having a terminal block attachedfor electrical connection;

a window 'mounted in the base member for side viewing;

an integral vent mounted in the bottom side of the base, and

an integral mounting nipple attached at the top side of the base;

a door movably mounted to the base member, the door being tubularcylindrical shape having an open end and a closed end, the open end ofthe door mating with the open end of the base when the door is in aclosed position,

the cylindrical shape of the door extends from the open end and is outalong a bias with the central axis of the door to form a hood as anintegral part of the door,

a lens is formed in the hood closing the end of the door along the bias;

a background-forming member having the shape of a circular plate,

the background-forming member has an aperture in the center so as to fitabout the hood, and a shape substantially concentrically waved along aradially transverse direction;

a lip protrusion is extending about the aperture formed in thebackground-forming member;

a plurality of ridge, stopping and groove members disposed about theperiphery of the door,

the groove, ridge and stopping members holding the background-formingmember in place,

the body of the background-forming member fitting into the grooveagainst the stopping member and the ridge holding the lip protrusion ofthe background-forming member in opposite directions.

1. A warning-light housing of unitized construCtion comprising: a basemember having an access port; a concave arcuate reflector integrallymounted to the base member; a lens member mounted to the base member; areceptacle mounted to the base member; the lens member, the receptacleand the reflector each aligned in predetermined position relative to theother and a background-forming member of substantially circular shape,the background-forming member having means for attachment to the warninglight housing, and the background-forming member having a shapesubstantially concentrically waved along a radially transversedirection.
 2. The housing of claim 1 wherein the reflector hassubstantially uniformly distributed random irregularities over itssurface.
 3. A warning-light housing of unitized construction comprising:a base member having an access port; a door mounted to the base memberfor closing the access port; a concave arcuate reflector integrallymounted to the base member; a receptacle mounted to the base member; alens integrally mounted to the door such that when the door is in aclosed position, the lens, the reflector and the receptacle are eachaligned in predetermined position relative to the other and abackground-forming member of substantially circular shape, thebackground-forming member having means for attachment to thewarning-light housing, and the background-forming member having a shapesubstantially concentrically waved along a radially transversedirection.
 4. The warning-light housing of claim 3 wherein the reflectorhas uniformly distributed random irregularities over its surface; and ahood is mounted to the door about the periphery of the lens.
 5. Thewarning-light housing of claim 4 wherein; the receptacle has a terminalblock attached thereto for electrical connection with a light source,and the receptacle holds the light source in an aligned predeterminedposition relative to the lens and reflector so that no focusingadjustment is necessary.
 6. The warning-light housing of claim 5wherein; a mounting nipple is attached to the base member; a window ismounted in the side of the base member; and a vent is mounted in theside of the base member.
 7. The warning-light housing of claim 6 havingan integrally mounted receptacle.
 8. A warning-light housing comprising:an arcuate concave reflector, the reflector having substantiallyuniformly distributed random irregularities over its surface ofproducing uniform light dispersion; and a background-forming member ofsubstantially circular shape, the background-forming member having meansfor attachment to the warning-light housing, the background-formingmember having a shape substantially concentrically waved, along aradially transverse direction.
 9. The reflector of claim 8 havingsubstantially the shape of a parabolic section wherein: a reflectivematerial is deposited upon the surface, the reflective material selectedfrom the group consisting of gold, silver, chromium, and aluminum.
 10. Awarning-light housing of unitized construction comprising incombination: a base member of tubular cylindrical shape, the base havingan open and closed end; an integral reflector mounted in the closed endof the base with the concave surface facing the open end, beingsubstantially the shape of a parabolic dish, and having uniformlydistributed random irregularities over its concave surface; the concavesurface plated with a reflective material; a receptacle mounted to thebase member having a terminal block attached for electrical connection;a window mounted in the base member for side viewing; an integral ventmounted in the bottom side of the base, and an integral mounting nippleattached at the top side of the base; a door movably mounted to the basemember, the door being tubular cylindrical shape having an open end anda closed end, the open end of the door mating with the open end of thebase when The door is in a closed position, the cylindrical shape of thedoor extends from the open end and is cut along a bias with the centralaxis of the door to form a hood as an integral part of the door, a lensis formed in the hood closing the end of the door along the bias; abackground-forming member having the shape of a circular plate, thebackground-forming member has an aperture in the center so as to fitabout the hood, and a shape substantially concentrically waved along aradially transverse direction; a lip protrusion is extending about theaperture formed in the background-forming member; a plurality of ridge,stopping and groove members disposed about the periphery of the door,the groove, ridge and stopping members holding the background-formingmember in place, the body of the background-forming member fitting intothe groove against the stopping member and the ridge holding the lipprotrusion of the background-forming member in opposite directions.